HD 200073

HD 200073
Location of HD 200037 and ζ Microscopii on the map (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Microscopium
Right ascension 21h 02m 27.16546s[1]
Declination −38° 31′ 51.4904″[1]
Apparent magnitude (V) 5.94[2]
Characteristics
Evolutionary stage red giant branch[3]
Spectral type K2 III[4] or K0 IV[5]
B−V color index +1.15[2]
Astrometry
Radial velocity (Rv)39±10[6] km/s
Proper motion (μ) RA: +156.842 mas/yr[1]
Dec.: −171.108 mas/yr[1]
Parallax (π)14.358 ± 0.0466 mas[1]
Distance227.2 ± 0.7 ly
(69.6 ± 0.2 pc)
Absolute magnitude (MV)+1.79[7]
Details
Mass1.03[8] M☉
Radius9.15±0.46[9] R☉
Luminosity28.8±0.3[1] L☉
Surface gravity (log g)2.75[8] cgs
Temperature4,569±50[10] K
Metallicity [Fe/H]−0.13[8] dex
Rotational velocity (v sin i)2.7±1.1[11] km/s
Age8.79+2.32
−2.04[12] Gyr
Other designations
43 G. Microscopii[13], CD−39°14079, CPD−39°8841, GC 29351, HD 200073, HIP 103836, HR 8046, SAO 212653, TIC 115011683[14]
Database references
SIMBADdata

HD 200073 (HR 8046; 43 G. Microscopii) is a solitary star located in the southern constellation Microscopium 8.5′ northwest of Zeta Microscopii. It is faintly visible to the naked eye as an orange-hued point of light with an apparent magnitude of 5.94.[2] The object is located relatively close at a distance of 227 light-years based on Gaia DR3 parallax measurements, but it is receding with a heliocentric radial velocity of 39 km/s.[6] At its current distance, HD 200073's brightness is diminished by an interstellar extinction of 0.13 magnitudes[15] and it has an absolute magnitude of +1.79.[7] It has a relatively high proper motion across the celestial sphere, moving at a rate of 213 mas/yr.[1]

HD 200073 has a stellar classification of K2 III,[4] indicating that it is an evolved K-type giant that has exhausted hydrogen at its core and left the main sequence. Astronomer David Stanley Evans gave a class of K0 IV,[5] indicating that it is a slightly evolved subgiant that is ceasing hydrogen fusion at its core. HD 200073 is currently on the red giant branch,[3] fusing hydrogen in a shell around an inert helium core. It has a comparable mass to the Sun[8] but at the age of 8.79 billion years,[12] it has expanded to 9.15 times the radius of the Sun.[9] It radiates 28.8 times the luminosity of the Sun[1] from its enlarged photosphere at an effective temperature of 4,569 K.[10] HD 200073 is slightly metal-deficient with an iron abundance of [Fe/H] = −0.13 or 74.1% of the Sun's.[8] It spins modestly with a projected rotational velocity of 2.7 km/s.[11]

  1. ^ a b c d e f g Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference Johnson1966 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Jones2011 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Houk1982 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Evans1964 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Kharchenko2007 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  8. ^ a b c d e Cite error: The named reference Wittenmyer2016 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Kervella2004 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Stassun2019 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference De Medeiros2014 was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference Soto2021 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Gould1879 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference SiMBAD was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Gontcharov2017 was invoked but never defined (see the help page).